Biomaterials and Inflammation

Genetic Defects

Apoptosis

Hypertrophy

Granulocytes

Presence of inflammatory cells

$Q or Jv = ([Pc - Pi] - \sigma[\pi_c - \pi_i])$

10,000 cells/cubic mm

Necrosis

Materials (biomaterials)

Presence of neutrophils

Macrophages

Regeneration

Permanent

Labile

Granulation Tissue

Fibrosis

Granulomas

Both destruction of tissue and repair by normal parenchyma

Short duration, exudative

Granulocytes, monocytes, lymphocytes

Inflammatory cells

$Q or Jv = ([Pc - Pi] - \sigma[\pi c - \pi i])$

Necrosis

Polymer collagen and other ECMs

Destruction of tissue

Protein

Destruction of tissue and repair by scar (fibrosis)

Necrosis = The summation of the morphologic changes following cell death in living tissue Apoptosis = Programmed cell death Hemostasis/Thrombosis = Sequence of events of biomaterial responses Granulation Tissue, Granulomas = Healing, fibrosis

Materials (biomaterials) = Cell injury Surgery = Cell injury Hypoxia = Cell injury Physical Agents = Cell injury

Labile = Cells that continuously divide and are therefore capable of regeneration Stable = Cells that do not normally divide, but are capable of regeneration Permanent = Cells that are unable to divide and therefore cannot regenerate Hypertrophy = Increase in cell size

Cell Injury = Reversible vs. irreversible Cell Death = Necrosis or apoptosis Adaptation = Cell's responses to stress Regenerative Capabilities of Cells = Depends on the cell type: Labile, Stable, Permanent

Immunologic Reactions = Cell injury cause Genetic Defects = Cell injury cause Nutritional Imbalances = Cell injury cause Microbiologic Agents = Cell injury cause

Acute Inflammation = Temporal pattern Chronic Inflammation = Temporal pattern Exudate = Main characteristic Transudate = Main characteristic

Acute Inflammation = Main theme: Surgery, Material Implanted Cell Injury and Necrosis Chronic Inflammation = Main theme: Healing, Fibrosis Granulation Tissue, Granulomas

Necrosis = The summation of the morphologic changes following cell death in living tissue Apoptosis = Programmed cell death

Hemostasis/Thrombosis = Sequence of events of biomaterial responses Necrosis = The summation of the morphologic changes following cell death in living tissue Apoptosis = Programmed cell death Granulation Tissue, Granulomas = Healing, fibrosis

Materials (biomaterials) = Cell injury cause Surgery = Cell injury cause Hypoxia = Cell injury cause Physical Agents = Cell injury cause

Acute Inflammation = Short duration, exudative, involving PMNs, and characterized by Calor, Rubor, Tumor, Dolor Chronic Inflammation = Long duration, involving macrophages/lymphocytes, proliferative cells-fibroblasts and blood vessels Transudate = Hemodynamic, non-inflammatory fluid with low protein content and specific gravity of 1.020 Exudate = Inflammatory fluid with high protein content and specific gravity greater than 1.020

Granulocytes = Include PMNs, Eosinophils, and Basophils Monocytes = Type of leukocyte involved in inflammation Lymphocytes = Type of leukocyte involved in inflammation Mast cells = Tissue cells, not found in circulating blood

Cell Injury = Any change in the cell's environment that is incompatible with its survival and normal function Necrosis = Type of cell death characterized by cell swelling, disintegration, and inflammation Leukocytosis = Abnormally high number of white blood cells in the blood Leukopenia = Abnormally low number of white blood cells in the blood

Hypertrophy = Increase in cell size or organ size due to increased workload Hyperplasia = Increase in cell number due to increased workload or hormonal stimulation Fibrosis = Formation of excessive fibrous connective tissue in an organ or tissue Fibrous Encapsulation = The process of forming a fibrous capsule around a biomaterial

Injury = First step in the sequence, leading to acute or chronic inflammation Acute Inflammation = Occurs hours to a few days after injury, involving hemodynamics, vascular permeability, and leukocyte migration Chronic Inflammation = Occurs after acute inflammation, involving macrophages/lymphocytes, fibroblasts, and blood vessels Granulation Tissue = Forms during the healing process, composed of new blood vessels and connective tissue

White Blood Cells (WBCs) = Also known as leukocytes, involved in the inflammatory response Normal Value = 10,000 cells/cubic mm in the blood Leukocytosis = Condition with increased numbers of white blood cells (>10,800/cubic mm) Leukopenia = Condition with decreased numbers of white blood cells

Local reaction of vascular (or vascularized) tissue to injury = Main characteristic of inflammation Destruction of tissue- or walling off of the biomaterial = One of the two main themes of inflammation and biomaterials Repair- by normal parenchyma or by scar (fibrosis) = One of the two main themes of inflammation and biomaterials Temporal Pattern = Short duration for acute inflammation, long duration for chronic inflammation

Q or Jv = Equation for fluid filtration in inflammation, where $Q$ or $Jv$ is the net filtration or fluid flow across the capillary wall $Pc - Pi$ = Hydrostatic pressure difference across the capillary wall $\pi_c - \pi_i$ = Osmotic pressure difference across the capillary wall $\sigma$ = Reflection coefficient, a measure of how well the capillary wall retains proteins

Reversible Growth Response = Cell growth response that can be reversed by removing the stimulus Irreversible Growth Response = Cell growth response that cannot be reversed even after removing the stimulus Hypertrophy = Increase in cell or organ size due to increased workload Hyperplasia = Increase in cell number due to increased workload or hormonal stimulation

PMNs = Type of white blood cell involved in acute inflammation Macrophages/Lymphocytes = Types of white blood cells involved in chronic inflammation Fibroblasts = Type of proliferative cell involved in chronic inflammation Blood Vessels = Involved in both acute and chronic inflammation

Materials (biomaterials), Surgery, Hypoxia, Physical Agents, Chemicals and Drugs, Microbiologic Agents, Immunologic Reactions, Genetic Defects, Nutritional Imbalances.

Necrosis and Apoptosis.

Atrophy, Hypertrophy, and Regeneration.

Reversible cell injury refers to the state where cells can recover and return to their normal functioning after a stressor is removed.

The main theme of acute inflammation is the immediate response to tissue injury or infection, characterized by the influx of leukocytes and the release of inflammatory mediators.

The main theme of chronic inflammation is the prolonged and persistent inflammation, often associated with tissue destruction and repair.

Necrosis refers to the morphologic changes following cell death in living tissue.

Apoptosis refers to programmed cell death, which is a controlled process of cell self-destruction.

The term used to describe the formation of scar tissue in healing tissue is fibrosis.

Materials (biomaterials), Surgery, Hypoxia, Physical Agents, Chemicals and Drugs, Microbiologic Agents, Immunologic Reactions, Genetic Defects, Nutritional Imbalances.

Apoptosis and necrosis

Short duration and exudative

PMNs (neutrophils)

Injury and necrosis

Fibrosis

Hyperplasia and fibrosis

Presence of inflammatory cells and high protein content

Macrophages and lymphocytes

Hypertrophy and hyperplasia

Destruction of tissue and repair by scar (fibrosis)

Destruction of tissue or walling off of the biomaterial, Repair by normal parenchyma or by scar (fibrosis)

Short duration, hours to a few days

Granulocytes (PMNs, Eosinophils, Basophils), Monocytes, Lymphocytes

Short duration

$J_v = ([P_c - P_i] - σ[π_c - π_i])$

Inflammation

Fibrosis

Repair by scar (fibrosis)

Presence of inflammatory cells

10,000 cells/cubic mm

Fibrosis

Polymer

Sequence

Cell Injury

Chronic

B

White

Granulocytes

growth response

fibrosis

surgery

redness

persistent inflammation

swelling

tissue destruction

cell death

$\text{(Net Filtration Rate)} = \text{(Hydrostatic Pressure)} - \text{(Colloid Osmotic Pressure)}$

adaptation